Sorry to stir the pot on such a 'controversial' topic, but I have questions to pose to those that might know.:twisted:
I understand and agree that no 'self-contained' (i.e. running from alternator charge) electrolysis cell system (Brown's Gas generator) can be usefully employed to improve the mileage of an engine,.....BUT,....
i) How much current would a suitably sized cell require to produce enough gas to make a useful difference?
ii) Would it be feasible to add a PV array (solar panel/s) charging your secondary battery (Isolated from the vehicles primary charging system) and use the charge from the secondary battery as your energy source for your Browns Gas generator?
Might not be any use for long trips, as I suspect that the current required would be more than that supplied by the PV array, but for the many vehicles that drive for up to a couple of hours in the morning on the way to work, and then the return trip the following evening, I found myself wondering if one couldn't perhaps create a basic form of "Hybrid".:angel:

